Waterborne vehicles



United States Patent WATFJRBORN'E VEHICLES Herbert G. Hasler, Bursledon,England, assignor to Dracone Developments Limited, London, England FiledMay '4, 195 9, Ser, No. 310,672 g Claims priority, application GreatBritain May 13, 19 58 '6 Claims. (Cl. 114-665) The invention relates topower-operated or towed flexible barges.

At certain critical speeds of a flexible barge, the bow or nose tends todive and cause the barge to execute unstable movements commonly termedporpoising. The critical speeds principally depend on the density of thecargo and the shape of the nose of the barge.

The invention aims to minimise the instability of waterborne vehicles bycounteracting their diving tendency and thus making them easier to towor propel.

According to the invention, the diving force exerted on the nose iscounteracted by providing one or more hydro foils which balance theeffect on the nose of speed variations. Each hydrofoil is preferably soshaped and mounted that it exerts a lifting force as the barge is beingpropelled or towed through the water. The hydrofoil should also bedesigned so that it exerts a minimum drag on the barge and is not liableto damage when striking waves or solid objects and so that it clearsitself of weed or other floating matter which may become attached to it.

The hydrofoil may be given a dihedral and can be pivotally or rigidlyattached either directly to the nose of the barge or to the tow rope.

Examples of the invention are illustrated diagrammatically in theaccompanying drawings, in which:

FIGS. 1 and 2 are side and end views, respectively, of the nose of abarge fitted with a hydrofoil according to the invention, and

FIGS. 3, 4; 5, 6; 7, 8; 13, 14, are corresponding views of bargm fittedwith modified hydrofoils.

Referring to the drawings, the hydrofoils in all the figures havedihalral.

In FIGS. 1 and 2 there is shown the nose 1 of a barge fitted directlywith an arcuate hydrofoil 2. The outermost ends of the hydrofoil breakthe water surface on both sides of the nose of the barge whereby therighting moment which is exerted is considerably increased. The outerends, however, could lie on the surface of the water so that one arm ofthe hydrofoil will penetrate more deeply whenever the nose 1 begins toroll.

The hydrofoils 3, 4 in FIGS. 3 and 4 are interconnected at 5 below thenose 1 to form a hydrofoil assembly similar to the single hydrofoil ofFIGS. 1 and 2 except that the assembly is substantially channel-shaped.

In FIGS. 5 and 6, two hydrofoils 6, 7 are interconnected by an arm 8above the nose 1, such arm 8 itself being in the form of a hydrofoilconnected to the nose.

FIGS. 7 and '8 illustrate three hydrofoils 10, 11, 12. The hydrofoils10, 11 act similarly to the hydrofoils 3, 4 in FIG. 4, but are notinterconnected, whilst the hydrofoil 12 is completely immersed.

'In FIGS. 11 and 12, the hydrofoil =12 in FIGS. 7 and 8 is replaced bytwo hydrofoils 13, 14 mounted parallel to the hydrofoils 10, 11respectively.

In the arrangement according to FIGS. 11-14, each hydrofoil is in theform of a ladder assembly on each side of the nose, that is to say, inthe form of a number of lifting members 16 interconnected one above theother by members 17 so that at normal speeds of the barge one or more ofthe upper lifting members is at or above the water level. The two ladderassemblies are connected to the barge by cross-members 18 (FIG. 12)which lie below the water and which may themselves be in the 2 form' oflifting members or a cross member 19 (FIG. 14) lying abovethe water. Ina modification of arrangement, the ladder assemblies can incorporatesome of the features 'ofthe, dihedral systems described above".

The hydrofoil 'accordingto the invention can be easily fitted or removedto or from the nose even when the barge is fully loaded and afloat.-"ltmaybe made of any suitable material which is either rigid orflexible,'solid or hollow. If the hydrofoil is itself made buoyant, itwill assist in keeping the barge afloatin'an upright position when" thebarge is at rest.

As aforementioned, the hydrofoil is designed principally to overcome thediving force exerted on the nose when the barge is in motion. Thelifting force exerted by the hydrofoil may, however, be such as to liftthe nose above its normal trim when the barge is being propelled ortowed at high speeds.

The angle between the cord of the hydrofoil and the longitudinal axis ofthe barge may be varied by means of adjustments which can be made whilstthe barge is in motion. The adjustment may be effected by means of amanual control or automatically by a mechanism that is influenced by andresponds to variable such as wave movement, direction and tension of thetow rope, and the like. Another way is to vary the angle differentiallyso that one side of the hydrofoil temporarily generates more liftingpower than the other side and this effect may be used to provideanti-rolling moment.

If the aforementioned angle of the cord of the hydrofoil is negative,the hydrofoil may also be used to cause the nose to trim more deeply, oreven cause the whole barge to dive and remain fully submerged.Additional hydrofoils may be fitted to parts of the barge other than thenose.

The invention provides several advantages. The barge can now be towed orpropelled at any desired speed Without the risk of diving, even if thebarge has little or no positive buoyancy. The whole barge may be made toadopt a position in the water which is better suited to propulsion onthe surface and to the negotiation of waves. The draft of the barge canbe reduced. By helping the nose to run steadily through the waterwithout causing rolling or yawing, the hydrofoil considerably reducesrolling and yawing of the remainder of the barge. The gain in efficiencyas effected by the hydrofoil more than offsets the slight extra dragcaused by the hydrofoil itself.

Whenever the tension of the tow rope slackens, the hydrofoil acts as anautomatic brake on the nose of the barge, because the lifting forceexerted by it causes the nose to be raised which in turn increases thedrag exerted by the hydrofoil because of the change in the angle ofincidence. This eflfect is of value in preventing the barge fromoverriding a slack or broken tow rope.

When the hydrofoil is mounted to exert a diving moment on the nose ofthe barge, the drag on the latter is reduced and it may be towed moresteadily in heavy seas.

I claim:

1. In combination, a partly submerged flexible barge which is adapted tobe towed or propelled, and surface piercing hydrofoil means mounted onthe barge adjacent its bow portion and being shaped and inclined so thatit exerts a lifting force on the bow portion of the barge as the bargeis moved through the water sufiicient to counteract the diving tendencyof the barge.

2. The structure of claim 1, and wherein the hydrofoil means extendslaterally outwardly and upwardly and is of sufficient length to exert ananti-rolling moment on the barge during towing or propulsion. 3. Thestructure of claim 1, and wherein said hydrofoil means defines adihedral angle.

4. The structure of claim 1, and wherein an outer end 3 4 portion ofsaidhydrofoil means normally lies adjacent 1,776,700 Pegna Sept. 23,1930 the water surface. 1,976,046 Tietjens Oct. 9, 1934 5. The structureof claimll, and wherein said hydrofoil 2,257,406 Von Burtenbach Sept.30, 1941 means comprises.at least two laterally outwardly .and up-2,274,200 Hill Feb. 24, 1942 wardly extending hydrofoil elementsinterconnected by 5 2,391,926 Scott Jan. 1, 1946 atleast one whichitself in the'formiof 1a -hydrofoil 2,649,266 1Darrieus Aug. 18, 1953element.

.6. The structure of Claim 1; and Wherimsidhytlrufdil FOREIGN PATENTSmeans 1s buoyant 9 1,154,146 France Oct. 28, 1957 .ReferencesCiledwinethe fileof this patent 10 1 9 France 3, 1953 UNITED STATESPATENTS 130L738 'Potter AprLZZ, 1919

